Inkjet head chip, driving method for inkjet head chip, inkjet head, and inkjet recording apparatus

Abstract

An inkjet head chip has an ink chamber containing ink, channels separated by piezoelectric elements and disposed parallel to each other along a width direction of the inkjet head chip, and a nozzle hole for discharging an ink droplet. The channels include a discharge channel disposed in a middle portion of the parallely disposed channels and communicating with the ink chamber and nozzle hole, dummy channels disposed outside of the discharge channel at respective ends thereof, and non-discharge channels toward the recording medium and supply of the ink from the ink chamber to the dummy channels is interrupted. The discharge of an ink droplet from the non-discharge channels toward the recording medium and the supply of ink from the ink chamber to the non-discharge channels are interrupted. The inkjet head chip is configured such that voltages are substantially simultaneously applied to one of the plurality of piezoelectric elements which is adjacent to the discharge channel and to one of the plurality of piezoelectric elements which is disposed between the dummy and non-discharge channels.

1. An inkjet head chip, comprising:
 an ink chamber for containing ink; 
 a plurality of piezoelectric elements deformable by applying a voltage; 
 a plurality of channels partitioned with the plurality of piezoelectric elements and disposed parallel to each other along a width direction of the inkjet head chip; and 
 a nozzle hole for discharging an ink droplet toward a recording medium; 
 wherein the plurality of channels comprise a discharge channel disposed in a middle portion of the parallely disposed plurality of channels, dummy channels disposed outside of the discharge channel at respective ends thereof, and non-discharge channels disposed outside of the respective dummy channels; 
 wherein the discharge channel communicates with the ink chamber via an ink introduction hole and with the nozzle hole; 
 wherein at least one of discharge of the ink droplet from the dummy channels toward the recording medium and supply of the ink from the ink chamber to the dummy channels is interrupted; 
 wherein the discharge of an ink droplet from the non-discharge channels toward the recording medium and the supply of ink from the ink chamber to the non-discharge channels are interrupted; and 
 wherein the inkjet head chip is configured such that voltages are substantially simultaneously applied to one of the plurality of piezoelectric elements which is adjacent to the discharge channel and to one of the plurality of piezoelectric elements which is disposed between the dummy and non-discharge channels. 
 
     
     
       2. An inkjet head chip according to  claim 1 ; wherein the inkjet head chip is configured such that substantially the same voltage is applied to the one of the plurality of piezoelectric elements which is adjacent to the dummy channel and to the one of the plurality of piezoelectric elements which is adjacent to the discharge channel. 
     
     
       3. An inkjet head chip according to  claim 2 ;
 wherein, of the parallely disposed plurality of channels, each of 1st to 5th channels inside of each of the non-discharge channels is a dummy channel. 
 
     
     
       4. An inkjet head comprising the inkjet head chip according to  claim 2 . 
     
     
       5. An inkjet recording apparatus, comprising:
 the inkjet head according to  claim 4 ; 
 ink supply means for supplying ink to the ink chamber of the inkjet head chip; and 
 recording medium transport means for transporting a recording medium so as to pass through a position opposed to the nozzle hole of the inkjet head chip. 
 
     
     
       6. An inkjet head chip according to  claim 1 ; wherein, of the parallely disposed plurality of channels, each of 1st to 5th channels inside of each of the non-discharge channels is a dummy channel. 
     
     
       7. An inkjet head comprising the inkjet head chip according to  claim 6 . 
     
     
       8. An inkjet recording apparatus, comprising:
 the inkjet head according to  claim 7 ; 
 ink supply means for supplying ink to the ink chamber of the inkjet head chip; and 
 recording medium transport means for transporting a recording medium so as to pass through a position opposed to the nozzle hole of the inkjet head chip. 
 
     
     
       9. An inkjet head comprising the inkjet head chip according to  claim 1 . 
     
     
       10. An inkjet recording apparatus, comprising:
 the inkjet head according to  claim 9 ; 
 ink supply means for supplying ink to the ink chamber of the inkjet head chip; and 
 recording medium transport means for transporting a recording medium so as to pass through a position opposed to the nozzle hole of the inkjet head chip. 
 
     
     
       11. A driving method for an inkjet head chip,
 the inkjet head chip comprising:
 an ink chamber for containing ink; 
 a plurality of piezoelectric elements deformable by applying a voltage; 
 a plurality of channels partitioned with the plurality of piezoelectric elements and disposed parallel to each other along a width direction of the inkjet head chip; and 
 a nozzle hole for discharging an ink droplet toward a recording medium; 
 
 wherein the plurality of channels comprise a discharge channel disposed in a middle portion of the parallely disposed plurality of channels, dummy channels disposed outside of the discharge channel at respective ends thereof, and non-discharge channels disposed outside of the respective dummy channels;
 wherein the discharge channel communicates with the ink chamber via an ink introduction hole and with the nozzle hole; 
 wherein at least one of discharge of the ink droplet from the dummy channels toward the recording medium and supply of the ink from the ink chamber to the dummy channels is interrupted; and 
 wherein the discharge of an ink droplet from the non-discharge channels toward the recording medium and the supply of ink from the ink chamber to the non-discharge channels are interrupted; 
 
 the driving method comprising applying, substantially simultaneously, a voltage to one of the plurality of piezoelectric elements which is adjacent to the discharge channel and a voltage to one of the plurality of piezoelectric elements which is disposed between the dummy channel and the non-discharge channel. 
 
     
     
       12. An inkjet head chip comprising:
 an ink chamber plate having an ink chamber for containing ink; 
 an actuator plate having a plurality of channels disposed parallel to each other along a width direction of the actuator plate, the plurality of channels comprising a plurality of discharge channels each communicating with the ink chamber and configured for discharging an ink droplet, a pair of dummy channels formed at opposite end portions of the actuator plate and configured so that the dummy channels do not communicate with the ink chamber and are incapable of discharging ink droplets, and a plurality of non-discharge channels arranged alternately with respect to the discharge and dummy channels and configured so that the non-discharge channels do not communicate with the ink chamber and are incapable of discharging ink droplets; and 
 a plurality of piezoelectric elements disposed in the plurality of channels and driven by a voltage signal for undergoing deformation to vary a volume in the channels to thereby eject ink droplets from the discharge channels, the plurality of channels and piezoelectric elements being configured so that when the piezoelectric elements are driven by the voltage signal, voltages are substantially simultaneously applied to the piezoelectric elements disposed in the discharge channels and to the piezoelectric elements disposed in the dummy and non-discharge channels. 
 
     
     
       13. An inkjet head chip according to  claim 12 ; further comprising a nozzle plate connected to an end surface of the actuator plate, the nozzle plate having a plurality of nozzle openings each disposed in communication only with respective ones of the discharge channels so that when the piezoelectric elements are driven by a voltage signal ink droplets are ejected from the discharge channels through the nozzle openings. 
     
     
       14. An inkjet head comprising the inkjet head chip according to  claim 13 . 
     
     
       15. An inkjet recording apparatus, comprising:
 the inkjet head according to  claim 14 ; 
 ink supply means for supplying ink to the ink chamber of the inkjet head chip; and 
 recording medium transport means for transporting a recording medium so as to pass through a position opposed to the nozzle openings of the nozzle plate so that during ejection from the nozzle openings, the ink droplets are discharged toward the recording medium. 
 
     
     
       16. An inkjet head chip according to  claim 12 ; wherein the ink chamber plate has a plurality of introduction holes via which the respective discharge channels communicate with the ink chamber so that ink from the ink chamber flows to the discharge channels; and wherein the dummy and non-discharge channels do not communicate with the ink chamber so that ink contained in the ink chamber does not flow into the dummy and non-discharge channels. 
     
     
       17. An inkjet head comprising the inkjet head chip according to  claim 12 .